1. Field of the Invention
The present invention relates to rotary breech apparatus for an automatic weapon of the open chamber type.
2. Description of the Prior Art
Open chamber breech mechanisms are designed to provide high rates of fire and typically employ multiple barrels arranged in a revolving cluster. Single or multiple feed and ejecting stations move cartridges into and out of a breech which is rotated by the propellant gases, or by means such as an electric motor or the like. Each barrel and an aligned firing chamber undergo unified rotation during firing about an axis parallel to and spaced from the barrel. The whirling mass of barrels is characterized by high inertial forces, complexity and significant manufacturing expense. In certain prior art systems only one barrel is used, but the firing chambers still rotate about an axis parallel to and spaced from the barrel. Each firing chamber is halted momentarily as it comes into alignment with the bore, and the consequent intermittent operation greatly reduces the rate of fire in such a system.
Sealing of the open side of the chamber is accomplished in many prior art systems by surrouding the rotatable breech with a sleeve open only at each feed station and at each ejecting station. Sealing of the chamber to prevent the unwanted escape of propellant gases is achieved by frictional engagement between the complemental faces of the sleeve and the cartridges in the breech chambers. This is conducive to cartridge jamming and slows the operation of the weapon.